In a statement on Friday the Trump campaign stated that “after meeting with law enforcement has determined that for the safety of all of the tens of thousands of people that have gathered in and around the arena, tonight’s rally will be postponed to another date.” This statement comes after ongoing violence at Trump rallies, including fistfights and scuffles between supporters and protesters.

At a new conference late Friday night a spokesman for the Chicago PD said “The Chicago Police Department had no role. In fact, I can tell you we did assure the Trump campaign that we had more than adequate resources outside the UIC Pavilion and that we guaranteed them we could provide safe access and exit for Mr. Trump.”

On Sunday Trump again claimed that Kansas City police asked him to cancel a rally planned there, as reported by the Kansas City Star reporter Steve Kraske. The KC City Manager later denied this claim on Twitter. The rally went on as planned, and pepper spray was used by police on the assembled protesters as seen in the following video. There is some mild cursing in this video.

Sources:
https://www.donaldjtrump.com/press-releases/statement-regarding-trump-campaign-chicago-rally-postponement
Chicago Police: We Never Told Trump Campaign To Shut Down Rally
http://www.theatlantic.com/politics/archive/2016/03/trump-dissembles-about-peaceful-assembly/473658/
https://twitter.com/stevekraske